Father's age discovered to be linked to Autism : article

The prevalence of autism diagnosis has been climbing steadily since the 70's. Part of this rise in diagnosis has been atributed to more sensitive testing and increased awareness about the condition. This explains about half of the increase.

Over the years many theories have been proposed, but not proven,  for such increased including environmental toxicants and iatrogenic (such as vaccines).

A recent article published in Nature brings forward one of the most solid theories  for a possible  cause of autism : increased paternal age.

This study, carried out in Iceland by a croup of geneticists provides some of the first solid scientific evidence for a true increase in  autism.
When comparing the average paternal age in the study group in Iceland  the researchers observed that the average age of fatherhood rose from 28 to 33 between 1980 and 2011.

Similarly  children born in 2011 will harbour 70 new mutations, compared with 60 for a children  born in 1980.
The majority such mutations are harmless, but the researchers in Iceland identified some that  are linked to conditions such as autism.

The real issue now is that since it is likely that  autism is multifunctional a prenatal test is very far away in the future,and may not be definitive ( it may only suggest increased risk).

So what is an older perspective father to do? Difficult question. This article in the New York Times tries to give some answers.

You can find the original Nature article here

Reproductive Technologies (ivf , icsi ) and the Risk of Birth Defects

A large Australian study has reviewed the birth outcomes  in babies conceived with assisted reproductive technologies.
Contrary to the sensationalistic article in the New York Times   the study found no increase in risk for conventional IVF.  Some increased risk was associated with ICSI but the risk was not present when frozen embryos generated with ICSI were used .This finding does not make much sense to me  suggesting that the final conclusion may be confounded by outside factors.

The main take home fact is that simply having suffered from infertility will increase a couple's risk for birth defects regardless of the treatment and this may be true even for children conceived later without the help of assisted reproduction.

See abstract of the article below:

 

Reproductive Technologies and the Risk of Birth Defects

Michael J. Davies, M.P.H., Ph.D., Vivienne M. Moore, M.P.H., Ph.D., Kristyn J. Willson, B.Sc., Phillipa Van Essen, M.P.H., Kevin Priest, B.Sc., Heather Scott, B.Mgmt., Eric A. Haan, M.B., B.S., and Annabelle Chan, M.B., B.S, D.P.H.

N Engl J Med 2012; 366:1803-1813May 10, 2012

Background

The extent to which birth defects after infertility treatment may be explained by underlying parental factors is uncertain.

Methods

We linked a census of treatment with assisted reproductive technology in South Australia to a registry of births and terminations with a gestation period of at least 20 weeks or a birth weight of at least 400 g and registries of birth defects (including cerebral palsy and terminations for defects at any gestational period). We compared risks of birth defects (diagnosed before a child's fifth birthday) among pregnancies in women who received treatment with assisted reproductive technology, spontaneous pregnancies (i.e., without assisted conception) in women who had a previous birth with assisted conception, pregnancies in women with a record of infertility but no treatment with assisted reproductive technology, and pregnancies in women with no record of infertility.

Results

Of the 308,974 births, 6163 resulted from assisted conception. The unadjusted odds ratio for any birth defect in pregnancies involving assisted conception (513 defects, 8.3%) as compared with pregnancies not involving assisted conception (17,546 defects, 5.8%) was 1.47 (95% confidence interval [CI], 1.33 to 1.62); the multivariate-adjusted odds ratio was 1.28 (95% CI, 1.16 to 1.41). The corresponding odds ratios with in vitro fertilization (IVF) (165 birth defects, 7.2%) were 1.26 (95% CI, 1.07 to 1.48) and 1.07 (95% CI, 0.90 to 1.26), and the odds ratios with intracytoplasmic sperm injection (ICSI) (139 defects, 9.9%) were 1.77 (95% CI, 1.47 to 2.12) and 1.57 (95% CI, 1.30 to 1.90). A history of infertility, either with or without assisted conception, was also significantly associated with birth defects.

Conclusions

The increased risk of birth defects associated with IVF was no longer significant after adjustment for parental factors. The risk of birth defects associated with ICSI remained increased after multivariate adjustment, although the possibility of residual confounding cannot be excluded. (Funded by the National Health and Medical Research Council and the Australian Research Council.)